Costco members are usually asked to show their membership cards at the door.
Business Insider spoke to seven Costco employees about what happens when a Costco member can't - or won't - show them their card.
They said that if you ever forget your membership card on a Costco run, bring your ID to the membership desk in order to snag a replacement.
It's an aggravating scenario for any Costco member - arriving at the warehouse only to find that you've forgotten your membership card.
Because Costco is a members-only warehouse club, members are expected to show their cards upfront. Typically, Costco locations have an employee or two situated at the store's entrance, to ensure that only members gain access to the warehouse.
But what happens when someone shows up without a card - or even refuses to show their card?
"Members would be asked to go to the membership department where we can supply them a new membership card or temporary pass," a Costco spokesperson told Business Insider in a statement."There are no known issues with members refusing this, as it is part of the Terms and Conditions when members sign up."
Business Insider asked seven Costco employees about how they're instructed to handle members - or people who claim to be members - who show up sans card.
A Costco employee from Minnesota said that it's often "tough," because "people typically flash their cards at us" without "giving us a chance to see the picture on the back."
"They come through that door so fast and furious that, if you had to look at the back of each card, you'd have a major traffic jam," a Nebraska-based employee told Business Insider. "Picture anywhere from 300 to 400 members coming through the entrance every half hour, plus their family members or 'guests.' There just isn't a way to police this. You just be cordial and keep them moving."
And an employee from Illinois told Business Insider that the most important verification comes later.
"At the door, the members just flash the card from a distance," the employee said. "Verification isn't needed until the member gets to the register."
But what happens if a visitor says they have forgotten their card - or even outright refuses to show their membership card - at the door?
According to the employees, that might depend on the warehouse.
"When a member refuses to show their membership at the door, they're asked to leave," a Pennsylvania-based employee told Business Insider. "Same thing if they show a card not belonging to them."
That's not enough to stop some shoppers, though.
"When I work the door, nobody enters without showing their card," a Washington-based employee told Business Insider. "Many have tried, but nobody does. I have heard that a few female employees have been buffaloed by some male members who have refused to show a card. In those cases a manager is called to intervene and the situation is quietly resolved."
But, according to employees, other Costco locations are less stringent about allowing access to the warehouse.
"We pretty much let them through," an employee from Kentucky told Business Insider. "We are not going to physically restrain someone."
In some cases, employees are actively discouraged from intervening.
"One of my coworkers got written up because a member complained about being asked to show their membership," the Costco employee from Nebraska said.
If the individual flashes a card that clearly doesn't belong to them, the employee from Kentucky said that employees will ask them "if the cardholder is with them."
"If they answer yes, we ask them to wait for the cardholder," the employee said. "If they ignore the question or keep walking into the store, most likely the cashier will notice at check-out and call a supervisor over to explain to the person that only the member can use the card as membership is non-transferable."
So if the policy apparently varies across warehouses, why does Costco even bother asking people to show their membership cards at the door?
Employees say the card policy serves to prevent problems from arising down the road, namely at check-out.
"Basically it's our first line of defence - and technically our only line of defence," a Costco employee from Canada told Business Insider. "It prevents non-members from filling a whole buggy with items, only to get to the cash register and find out they need a membership. We've had this happen so many times."
And if the frustrated shopper ends up storming out, that leaves employees to return the "$US400 worth of frozen and freshly cooked items" to where they belong in the warehouse, accdording to the employee from Canada.
The employee from Illinois said that, while the warehouse will often refuse to sell to non-members, management sometimes caves if the customer throws enough of a fit.
"The supervisor will allow them to pay cash or debit," the employee said. "That comes with a firm warning that the cards are non-transferable, but no one really listens to rules anyways. There are lots of cashiers that don't enforce those rules - that's why the non-members feel they can get away with it so many times."
But if you are a legitimate Costco member who shows up without your card, you do have one method of recourse.
"If the member doesn't have their card, they just need to swing by the membership desk with ID and we print them either a temporary card or a brand new card," the employee from Minnesota told Business Insider. "There's no limit on how many times you can get a new card or a temporary."
"I don't think there is a specific protocol, you try to handle each situation as it comes," an employee from Nebraska said. "Most members are pretty upfront if they forgot their card. They will go right to the member service desk."